How to: Set the Expiration Period for Subscriptions (SQL Server Management Studio)
Set the expiration period for subscriptions on the General page of the Publication Properties - <Publication> dialog box. For more information about accessing this dialog box, see How to: View and Modify Publication and Article Properties (SQL Server Management Studio).
The subscription expiration period is also referred to as the publication retention period. Cleanup of merge replication metadata is dependent on this setting:
Replication cannot clean up metadata in the publication and subscription databases until the retention period is reached. Use caution in specifying a high value for the retention period, because it can negatively impact replication performance. It is recommended that you use a lower setting if you can reliably predict that all Subscribers will synchronize regularly within that time period.
The retention period for merge publications has a 24 hour grace period to accommodate Subscribers in different time zones. If, for example, you set a retention period of one day, the actual retention period is 48 hours.
It is possible to specify that subscriptions never expire, but it is strongly recommended that you do not use this value, because metadata cannot be cleaned up.